This invention relates to the field of microsystems characterization systems, and particularly to microelectromechanical microsystems characterization systems.
The present invention comprises a testing and characterization system to provide automated multi-domain measurements of a wide range of microsystem devices in either single chip or wafer format. Unlike electronic devices and integrated circuits in which only lumped electrical parameters are needed for device level modeling, microsystem devices require the precise and simultaneous measurement of multi-domain parameters, often widely dissimilar. In the microelectrical domain, probe stations, waveform generators and current-voltage measurement equipment are all instruments used for modeling and or testing based on lumped electrical circuits. However, they are not capable of providing characterization of the mechanical or fluidic properties common in microsystem devices.
Typical microsystem devices that would benefit from the testing and characterization capabilities of the present invention include present and future devices with vibratory or bistable motion in either the horizontal or vertical direction, fluidic properties, or optical properties. Such devices include but are not limited to accelerometers, diffraction gratings, pumps, gyroscopes, micromirrors, micromicrophones, drive motors. actuators and diaphragms.
Current technology and prior art carried over from electronic device testing tend to provide means for testing a few characteristics of the micros,stem devices, primarily electrical. However, these technologies often lack the ability to characterize the results of the electrical stimulus, i.e. mechanical motion. Similarly, prior art exists that is capable of non-contact examination of the topology of wafers or devices in search of structural defects, but these systems too are incapable of characterizing the mechanical motion or fluidic operation of these wafers or devices. Overall, they lack an overall multi-domain characterization ability that is needed to establish the microsystem devices as viable components suitable for full scale manufacturing.
For example, U.S. Pat. No. 5,773,951 by Markowski and Cosby provides a means of wafer only level electrical probing. As discussed above, this technology is capable of testing and verifying the electrical contacts of the microsystems device, but is unable to characterize the operation resulting from the electrical stimulus.
Similarly, several U.S. patents appear to disclose non-contact surface profiling in the determination of structural defects. These include U.S. Pat. No. 5,127,726 by Moran which provides a high resolution surface inspection system: U.S. Pat. No. 5,105,147 by Karasikov and Ilssar which provides a optical inspection system for wafers; U.S. Pat. No. 4,607,525 by Turner and Roch which provides an air probe for wafer contouring. U.S. Pat. No. 5,526,116 and U.S. Pat. No. 5,671,050 by de Groot which provide an optical means of surface profiling for wafer inspection; and U.S. Pat. No. 5,479,252 by Worster .et al., which provides a confocal laser scanning system for defect detection in wafers. However, these systems often lack the ability to provide electrical stimulus to characterize the resultant surface structure or more importantly, to perform microsystem operation.
Therefore, it is the object of the invention disclosed herein to provide an integrated testing and characterization system for wafer level microsystem technologies.
It is also an object of the invention to provide an integrated testing and characterization system for die level microsystem technologies.
The present invention provides an improved microsystems testing system. By identifying specific structures, the user can initiate an automated testing sequence 106 to be implemented on that structure or a series of structures. The integrated control system that governs the present invention automates power supply to the device under test 101, precision motion control of all components, sensor 134 operation, data processing and data presentation. Therefore operation is autonomous once the microstructure is in place and the testing sequence is specified. The integrated testing system can be used to perform tests on an entire wafer or on a single die.